I. Field of the Invention
The present invention relates generally to medical instruments and, more particularly, to a scleral marker for use in ophthalmic procedures.
II. Description of Related Art
In many ophthalmic procedures it is essential to locate the point of injection into the scleral limbal tissue at a precise location in order to ensure safety not only of the eye lens but also the PARS Plana region. For a human adult eye, the safe PARS Plana region lies at about 3.5 mm from the outer edge of the iris. Such a position essentially ensures not only safety of the retina, but also protects the lens from damage.
In order to facilitate the correct position in the scleral before the injection, there have been previously known devices known as “Melki” markers. This previously known Melki marker include an elongated handle dimensioned to be held in the hand of the surgeon. A pair of pointers extend outwardly from one end of the handle in the free ends of these two pointers are separated from each other by the desired distance, e.g. 3.5 mm.
In use, a Melki marker is pressed against the eye and moved for a short distance along the outside of the iris thus causing a depression in the sclera. It has been found that insertion of a needle through the depressed area, necessary for many medical procedures, is essentially painless to the patient.
In practice, however, it is difficult for even skilled ophthalmic surgeons to constantly accurately inject the needle into the depression caused by the Melki marker. When this happen; the patient feel a pain sensation in the eye. In Opthamology, however, the avoidance of pain for the patient is paramount.